As a tool for helping a passenger to walk between floors or reducing a walking distance of the passenger, a passenger conveyor is very common in daily life. For example, an escalator usually used between floors of a commercial building and a moving walk usually used in a large airport are especially common.
For such a tool, a lighting device may usually be arranged at multiple positions of the passenger conveyor in order to make it easy for a passenger to take the conveyor or provide an indication or for the purpose of beauty. For example, a traffic flow lamp is arranged at an entry of the passenger conveyor; a comb lamp or a step lamp is arranged at steps of the passenger conveyor; a handrail lamp is arranged on a moving handrail of the passenger conveyor; and barrier lamps are arranged on barriers on two sides of the passenger conveyor. When a corresponding lighting device no longer works due to a failure, it may lead to a corresponding lack of the technical effect brought by the lighting device. Besides, in consideration of different requirements on a light intensity due to changes in an application environment and changes in the environment with time, if the light intensity of the corresponding lighting device could be adjusted correspondingly to adapt to the environment, a further energy-saving effect may be provided.